论文标题
在稀释温度下，超敏感的纳米机械力传感器
Ultrasensitive nano-optomechanical force sensor at dilution temperatures
论文作者
论文摘要
冷却纳米力学探针是一种通用策略，可以通过降低其热噪声和机械阻尼速率来增强其敏感性。但是，在低温下，热传导机制的效率降低，这使得难以确保和验证其适当的热化。为了使用最小的扰动测量，我们实施了在光子计数方案中运行的光力读数技术，以探测稀释冰箱中悬浮硅碳化物纳米线的动力学。在每个振荡周期收集少于一个光子的状态下，通过亚皮科瓦特光学能力来实现其振动的读数。我们证明了它们的热化至$ 32 \ pm2 $ MK，并报告了扫描探针传感器的记录敏感性，价格为$ 40 \，\ rm zn/hz^{1/2} $ evelp，对FN/m范围中的横向力场梯度具有敏感性。这项工作为在稀释温度下，在最小的激发水平下，在稀有力温度下通往纳米力学矢量成像的道路。
Cooling down nanomechanical force probes is a generic strategy to enhance their sensitivities through the concomitant reduction of their thermal noise and mechanical damping rates. However, heat conduction mechanisms become less efficient at low temperatures, which renders difficult to ensure and verify their proper thermalization. To operate with minimally perturbing measurements, we implement optomechanical readout techniques operating in the photon counting regime to probe the dynamics of suspended silicon carbide nanowires in a dilution refrigerator. Readout of their vibrations is realized with sub-picowatt optical powers, in a regime where less than one photon is collected per oscillation period. We demonstrate their thermalization down to $32\pm2$ mK and report on record sensitivities for scanning probe force sensors, at the $40\,\rm zN/Hz^{1/2}$ level, with a sensitivity to lateral force field gradients in the fN/m range. This work opens the road toward nanomechanical vectorial imaging of faint forces at dilution temperatures, at minimal excitation levels.
